1. Field of the Invention
This invention relates to a unitary joist hanger, particularly for hanging metal joists of C-shaped cross-section from headers. In the preferred embodiment, the hanger has a top flange that rests on the top surface of the header, a first back flange, a central flange that is fastened to the web of the supported C-shaped metal joist, and a second back flange. A pair of tabs is bent forward out of the first back flange, one of which positions and supports the C-shaped metal joist, depending on the orientation of the C-shaped metal joist to the left or to the right of the central flange. The upper flange of the C-shaped metal joist rests on the tab.
2. Description of the Prior Art
There are a number of unitary joist hangers particularly adapted for supporting metal joists of C-shaped cross-section from headers. However, many of these interface with the lower flange of the C-shaped metal joist so they can only support one size of C-shaped metal joist flush with the top of the header. U.S. Pat. No. 3,945,741, granted to Alan C. Wendt on Mar. 23, 1976, describes such a hanger for mounting hollow metal joists. The back plate terminates at its bottom edge in a saddle for the joist to rest upon. U.S. Pat. No. 5,836,131, granted to Ernest S. Viola et al on Nov. 17, 1998, also describes a one-piece joist hanger with a lower tab member that the joist rests upon. C-shaped metal joists come in a variety of sizes, varying in both height and width.
Among hangers not limited to a certain size joist, some only permit either a left or right orientation of the C-shaped metal joist, but not both. Viola '131 exemplifies the type of hanger that permits only a left or right orientation of the C-shaped metal joist.
Among unitary joist hangers, only a few can both hang C-shaped metal joists in a variety of sizes flush with the top of the header and permit both left and right orientations of the C-shaped metal joist. These however fail to achieve the economy of material of the present invention and have neither the versatility or ease of installation of the present invention, due to structural limitations. U.S. Pat. No. 3,907,445, granted to Alan C. Wendt on Sep. 23, 1975, is an example of this type of hanger.